We have run 3mm dynemaa lines for or trapezes "forever". Chafe was not an issue for us, the lines lasted several years.
Perhaps it is design specific, but i was recently told that during a race, 2 "regulars here" barely made it through a single use (race) before the tops were "spent" (on a mystere 6.0 which basically is the same design as my cat, just a little more volume in the hulls)
I do know there is some real rubbing going on up top with my rig...
